(A) Schematic of the MAPK cascade, reproduced from [26], 1996. The full MAPK cascade consists of ten enzymatic reactions where each step is modeled by mass action; it can be described by an ODE system consisting of 15 variables and 37 parameters. The distinguished (bifurcation) parameter, pb ∈ R+, is the cascade input (the total concentration of E1). The 36-dimensional vector of the remaining model parameters (p ∈ R+36) consists of 30 rate constants and six total concentrations).
(B) Schematic of the sampling/continuation approach. The components of the remaining model parameters are generated from the 36-dimensional vector of predefined base values (pc ∈ R+36) and the random variables ɛi that are uniformly distributed in [−q, q], where q is the size of the uncertainty interval: pi = pci × 5ɛi, i = 1, 2, … 36.